Migrate clang5-mobile build to GHA (#66673)
Summary:
`linux-xenial-py3-clang5-mobile-build`, `linux-xenial-py3-clang5-mobile-custom-build-dynamic`, `linux-xenial-py3-clang5-mobile-custom-build-dynamic` and `linux-xenial-py3-clang5-mobile-code-analysis` are just the flavors of regular linux build job with no tests.
`linux-xenial-py3-clang5-mobile-code-analysis` is the master only job
`code-analysis` job is dispatch to `.jenkins/pytorch/build-mobile-code-analysis.sh` in
https://github.com/pytorch/pytorch/blob/583217fe37de6242c71d7928bf632baa3817990b/.jenkins/pytorch/build.sh#L23-L25
and all `mobile-build` jobs are dispatched to `.jenkins/pytorch/build-mobile.sh` in
https://github.com/pytorch/pytorch/blob/583217fe37de6242c71d7928bf632baa3817990b/.jenkins/pytorch/build.sh#L19-L21
Rename `is_libtorch` `CIWorkflow` property into `build_generates_artifacts` and change defaults from False to True
Both libtorch and mobile build jobs do not generate build artifacts
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66673
Reviewed By: janeyx99
Differential Revision: D31674434
Pulled By: malfet
fbshipit-source-id: 24d05d55366202cd4d9c25ecab429cb8f670ded0
